The cleaning and spray coating of the interior surfaces of industrial chemical-reaction vessels has long been a problem. In the practice of many commercial chemical processes reaction vessels become coated with undesirable reaction products which must be periodically removed. To avoid subjecting maintenance personnel to the unpleasant and often hazardous task of entering the vessel and mechanically washing or scraping the sidewalls and interior surfaces, various types of mechanical devices have been utilized to accomplish the cleaning. These devices include rotating spray heads which are introduced into the vessel to discharge a pressurized stream of water or other solvent to dislodge the accumulated material. After the interior surface has been cleaned, it is then often spray-coated with a release agent to facilitate the next cleaning operation. These prior art spraying devices have generally required extensive and complicated mechanical linkages between nozzles and the electric motors which gradually insert the spray nozzle into the vessel. In addition to the electrical and mechanical hook-ups, flexible conduits were required for transmitting the cleaning liquid or solvent from the storage container to the apparatus. This apparatus, in addition to being complicated and cumbersome was subject to frequent breakdowns and required considerable maintenance to keep it in proper operating condition. In addition to the problems inherent with this type of complex mechanical spraying apparatus, such apparatus had to be either removed from the tank to protect it from the effects of weather if the reaction vessels were located outside, or the cleaning apparatus had to be provided with an adequate structural protective housing. Even if the apparatus were mounted on a reaction vessel located indoors special care had to be exercised to prevent damage from overhead cranes or other material-handling equipment operating in the area.
It is therefore an object of the present invention to provide apparatus for spray cleaning and coating the interior surfaces of reaction vessels which have the following characteristics and advantages:
(a) eliminates the need for personnel to enter the interior of the vessel; PA1 (b) are permanently mounted on the exterior surface of the vessel; PA1 (c) are inserted into the interior of the vessel during the spraying operation and withdrawn prior to the next use of the vessel; PA1 (d) are readily isolated from the atmosphere of the reaction vessel when withdrawn; PA1 (e) are protected from the natural environment and elements, and from damage as a result of inadvertent or careless actions of operating personnel; PA1 (f) eliminates the need for complicated mechanical linkages and external sources of direct mechanical power and the use of flexible hosing and conduits; PA1 (g) utilizes hydraulic or pneumatic pressure to move the spraying means into and out of the reaction vessel; PA1 (h) utilizes the same pressurized fluid that is sprayed to move the spray means into and out of the vessel; PA1 (i) reduces substantially the time cycle for cleaning and/or spraying the vessel; and PA1 (j) reduces maintenance time and expense.
Further objects and advantages will become apparent from the detailed description of the invention which follows.